Sooo my bount rivision is basically done, now i have a question to ask seeing as hollows are coming next... Which order should they go in? How often should they evolve? What kind of skills would you like to see?

Only Menos, Adjuchas, and Vasto get to become Arrancars. They must be mutated by the hygoku to do so. Staying a hollow means you can continue to live the way you were and have a less likely hood to die.

Only Menos, Adjuchas, and Vasto get to become Arrancars. They must be mutated by the hygoku to do so. Staying a hollow means you can continue to live the way you were and have a less likely hood to die.

Being a arrancar and, eventually, an espada means more power.

thats untrue, their are "Natural" Made arrancars, and this is why they can -stay- hollows, or become Arrancars on a level that is higher than the level they will advance to a gillian.

I can agree with that. But Starrk and Lili were once one. A vasto lordes. lonely but born with the rare abilities to split their soul, became two different beings. In this, they weren't arrancar because Lili was not a zanpkunton until after the Hygo process. So, to become an arrancar without aizen would tae decades upon centuries and it's almost impossible to do so.

There was no confirmation that Stark was a vasto lorde though Kite claimed that there were vasto lorde grouped Arrancars, but we don't even know if the ranking system was correct (considering Ulquiorra's Bankai.)

Though apparently I checked up to see if what I said was wrong and we're both partially right. Arrancars can naturally be born, they're just rare to come by because a Hollow would have to get so strong and lonely(basically the story of Stark) in order to split themselves and make that part of them their Zanpakutou. Lilli was a Zanpakutou just wasn't realized yet because he didn't get the Hougyoku, but I'm assuming this still couldn't naturally happened on its own.

Apparently the Hougyoku just makes them complete faster since it brings out the full potential pretty much immediately. So if they didn't have the ability to do this naturally the Hougyoku wouldn't do it.